Hmm, part of me says you shouldn't have to because the are already sterile. Part of me wonders if they could get contaminated at the opening while pouring it. you are talking about actual cartons, the kind where you rip it in half and push back to open, like those things they sell smaller quantities of milk in? I always struggle to open those, and the fact that I would be handling the opening so much would probably make me want to add some potassium metasulfite.

Hmm, part of me says you shouldn't have to because the are already sterile. Part of me wonders if they could get contaminated at the opening while pouring it. you are talking about actual cartons, the kind where you rip it in half and push back to open, like those things they sell smaller quantities of milk in? I always struggle to open those, and the fact that I would be handling the opening so much would probably make me want to add some potassium metasulfite.

They had screw corks luckily! If I had to rip them open I would have sprayed them with a sanatizer first.